Electronic phase separation in TmBa2Cu4O8

The NQR spectra of Cu(2) in the superconductor TmBa2Cu4O8 are studied at temperatures from 300 to 4.2 K. In analyzing the spectra it is assumed that the NQR line of each isotope contains two Gaussian components - narrow (n) and broad (b). It is discovered that the NQR frequencies have a minimum at the temperature T* = 150 K. The frequencies of the components of the spectrum are close at temperatures from T* to 4.2 K and differ substantially at temperatures T>T*. Both components are broadened as the temperature decreases, but this broadening occurs especially rapidly at temperatures T<T*. The relative intensity of the narrow component In/(In+Ib) equals 1/6 for T = 225-160 K, increases abruptly at T = T*, and remains constant (1/3) at temperatures T from 125 to 4.2 K. Analysis of the experimental data showed that the anomalous temperature dependences of the Cu(2) NQR spectra could be due to electronic phase separation (stratification) in the CuO2 planes at temperatures T ≤ T*. © 1996 American Institute of Physics

Estimation Level by the Student Youth of the Ecological Special Features of Water Use.

Досліджено специфічні особливості води (“пам’ять води”) з використанням процесу бродіння рису у водному середовищі. Методом анкетування визначено оцінку студентами молодших курсів хімічного факуль-тету ВНУ імені Лесі Українки здатності води зберігати інформацію про можливий вплив людини на еколо-гічний стан води. Більшість респондентів вважає, що вода може “помститися” людству за погане відношення та забруднення. The specific special features of water (“the memory of water”) with the use of fermentation process of rice in the aqueous medium are investigated. Via questioning was determined estimation by the students of the low-order policies of the chemistry department VNU of the name of Lesya Ukrainka of the ability of water to preserve information about the possible influence of man on the ecological state of water. The majority of respondents considers that water can “take vengeance” upon humanity for the bad treatment and the pollution.Роботу виконано на кафедрі екології та охорони навколишнього середовища ВНУ ім. Лесі Українк

MISHIMA - a new method for high speed multiple alignment of nucleotide sequences of bacterial genome scale data

<p>Abstract</p> <p>Background</p> <p>Large nucleotide sequence datasets are becoming increasingly common objects of comparison. Complete bacterial genomes are reported almost everyday. This creates challenges for developing new multiple sequence alignment methods. Conventional multiple alignment methods are based on pairwise alignment and/or progressive alignment techniques. These approaches have performance problems when the number of sequences is large and when dealing with genome scale sequences.</p> <p>Results</p> <p>We present a new method of multiple sequence alignment, called MISHIMA (Method for Inferring Sequence History In terms of Multiple Alignment), that does not depend on pairwise sequence comparison. A new algorithm is used to quickly find rare oligonucleotide sequences shared by all sequences. Divide and conquer approach is then applied to break the sequences into fragments that can be aligned independently by an external alignment program. These partial alignments are assembled together to form a complete alignment of the original sequences.</p> <p>Conclusions</p> <p>MISHIMA provides improved performance compared to the commonly used multiple alignment methods. As an example, six complete genome sequences of bacteria species <it>Helicobacter pylori </it>(about 1.7 Mb each) were successfully aligned in about 6 hours using a single PC.</p

Accretion in dipole magnetic fields: flow structure and X-ray emission of accreting white dwarfs

Field-channelled accretion flows occur in a variety of astrophysical objects, including T Tauri stars,magnetic cataclysmic variables and X-ray pulsars. We consider a curvilinear coordinate system and derive a general hydrodynamic formulation for accretion onto stellar objects confined by a stellar dipole magnetic field. The hydrodynamic equations are solved to determine the velocity, density and temperature profiles of the flow. We use accreting magnetic white-dwarf stars as an illustrative example of astrophysical applications. Our calculations show that the compressional heating due to the field geometry is as important as radiative cooling and gravity in determining the structure of the post-shock flow in accreting white-dwarf stars. The generalisation of the formulation to accretion flows channelled by higher-order fields and the applications to other astrophysical systems are discussed.Comment: Accepted A&

Inclusive meson production in peripheral collisions of ultrarelativistic heavy ions

There exist several proposals to use Weizs\"{a}cker-Williams photons generated by ultrarelativistic heavy ions to produce exotic particles in $\gamma\gamma$ fusion reactions. To estimate the background conditions for such reactions we analyze various mechanisms of meson production in very peripheral collisions of ultrarelativistic heavy ions at RHIC and LHC energies. Besides $\gamma\gamma$ fusion they include also electromagnetic $\gamma A$ interactions and strong nucleon-nucleon interactions in grazing $AA$ collisions. All these processes are characterised by low multiplicities of produced particles. $\gamma A$ and $AA$ events are simulated by corresponding Monte Carlo codes, RELDIS and FRITIOF. In each of these processes a certain fraction of pions is produced close to the mid-rapidity region that gives a background for the $\gamma\gamma$ events. The possibility of selecting mesons produced in $\gamma\gamma$ fusion events via different $p_t$ cut procedures is demonstrated.Comment: 27 pages with 4 eps-figures included, uses axodraw.sty Tab.2 and 3 correcte

Radiation Embrittlement Understanding for PLIM Activities at EC-JRC-IE

Radiation embrittlement and aging mechanisms for NPP reactor pressure vessels and vessel internals have been studied within NPP Plant Life Management (PLIM) for evaluation, prediction, and monitoring of the critical components’ service life. The main achievements of the SAFELIFE project, integrating various networks on PLIM issues, are given. Results of neutron embrittlement of model alloys are presented, and surveillance and research data on WWER reactor pressure vessel and other steels have been analyzed. Projects for the development of destructive and non-destructive testing of irradiated materials have been outlined.В рамках программы PLIM исследовано радиационное охрупчивание и механизмы старения конструкционных сталей внутрикорпусных устройств реакторов с целью оценки, прогнозирования и мониторинга ресурса ответственных узлов АЭС. Изложены результаты проекта SAFELIFE, объединяющего различные подходы к контролю ресурсом АЭС. Представлены результаты радиационного охрупчивания модельных сплавов, проанализированы данные испытаний с использованием образцов-свидетелей, а также исследована надежность корпусных и других типов сталей. Предложены перспективы развития разрушающих и неразрушающих методов радиационного охрупчивания материалов.У рамках програми PLIM досліджено радіаційне окрнхчування і механізми старіння конструкційних сталей та реакторів із метою оцінки, прогнозування і моніторинга ресурсу відповідальних вузлів АЕС. Підсумовуються результати проекту SAFELIFE, що об’єднує різні підходи щодо контролю ресурсом АЕС. Представлено результати радіаційного окрихчування модельних сплавів, проаналізовано дані випробувань із використанням зразків- свідків, а також досліджується надійність корпусних та інших типів сталей. Запропоновано перспективи розвитку руйнівних і неруйнівних методів радіаційного окрихчення матеріалів

Selenoprotein gene nomenclature

The human genome contains 25 genes coding for selenocysteine-containing proteins (selenoproteins). These proteins are involved in a variety of functions, most notably redox homeostasis. Selenoprotein enzymes with known functions are designated according to these functions: TXNRD1, TXNRD2, and TXNRD3 (thioredoxin reductases), GPX1, GPX2, GPX3, GPX4 and GPX6 (glutathione peroxidases), DIO1, DIO2, and DIO3 (iodothyronine deiodinases), MSRB1 (methionine-R-sulfoxide reductase 1) and SEPHS2 (selenophosphate synthetase 2). Selenoproteins without known functions have traditionally been denoted by SEL or SEP symbols. However, these symbols are sometimes ambiguous and conflict with the approved nomenclature for several other genes. Therefore, there is a need to implement a rational and coherent nomenclature system for selenoprotein-encoding genes. Our solution is to use the root symbol SELENO followed by a letter. This nomenclature applies to SELENOF (selenoprotein F, the 15 kDa selenoprotein, SEP15), SELENOH (selenoprotein H, SELH, C11orf31), SELENOI (selenoprotein I, SELI, EPT1), SELENOK (selenoprotein K, SELK), SELENOM (selenoprotein M, SELM), SELENON (selenoprotein N, SEPN1, SELN), SELENOO (selenoprotein O, SELO), SELENOP (selenoprotein P, SeP, SEPP1, SELP), SELENOS (selenoprotein S, SELS, SEPS1, VIMP), SELENOT (selenoprotein T, SELT), SELENOV (selenoprotein V, SELV) and SELENOW (selenoprotein W, SELW, SEPW1). This system, approved by the HUGO Gene Nomenclature Committee, also resolves conflicting, missing and ambiguous designations for selenoprotein genes and is applicable to selenoproteins across vertebrates

Synchronous bursts on scale-free neuronal networks with attractive and repulsive coupling

This paper investigates the dependence of synchronization transitions of bursting oscillations on the information transmission delay over scale-free neuronal networks with attractive and repulsive coupling. It is shown that for both types of coupling, the delay always plays a subtle role in either promoting or impairing synchronization. In particular, depending on the inherent oscillation period of individual neurons, regions of irregular and regular propagating excitatory fronts appear intermittently as the delay increases. These delay-induced synchronization transitions are manifested as well-expressed minima in the measure for spatiotemporal synchrony. For attractive coupling, the minima appear at every integer multiple of the average oscillation period, while for the repulsive coupling, they appear at every odd multiple of the half of the average oscillation period. The obtained results are robust to the variations of the dynamics of individual neurons, the system size, and the neuronal firing type. Hence, they can be used to characterize attractively or repulsively coupled scale-free neuronal networks with delays.Comment: 15 pages, 9 figures; accepted for publication in PLoS ONE [related work available at http://arxiv.org/abs/0907.4961 and http://www.matjazperc.com/