52 research outputs found
Interaction between Earthworms and Soil-Inhabiting Anthrax Microbe Spores
Studied are phenotypic and genetic properties of anthrax agent strains, isolated from earthworms retained in infected soil for a period of 20 and 30 days. Discovered is the fact that the presence of worms in the biotope reduces the number of Bacillus anthracis spores by 30-50 %. However, the rest of the spores preserve original properties, and biological and genetic virulence dominants
Crystal chemistry aspects of the magnetically induced ferroelectricity in TbMn2O5 and BiMn2O5
The origin of magnetic frustration was stated and the ions whose shift is
accompanied by emerging magnetic ordering and ferroelectricity in TbMn2O5 and
BiMn2O5 were determined on the basis of calculation of magnetic coupling
parameters by using the structural data. The displacements accompanying the
magnetic ordering are not polar, they just induce changes of bond valence
(charge disordering) of Mn1 and Mn2, thus creating instability of the crystal
structure. To approximate again the bond valence to the initial value (charge
ordering) under magnetic ordering conditions is possible only due to polar
displacement of Mn2 (or O1) and O4 ions along the b axis that is the cause of
ferroelectric transition.Comment: 17 pages, 3 figures, 5 table
Identification of Bacillus anthracis Isolated from Soil of the Animal Burial Site
The usage of modern gene engineering methods makes it possible not only to identify anthrax strains isolated from soil, but also to hold out comparative molecular genetic assays with these strains. Carried out was the laboratory research of 80 soil samples isolated from the old animal burial site using microbiological and genetic techniques. Epidemiological significance of the isolated strains was evaluated on the basis of the results of PCR with species-specific primers and multi-locus VNTR-analysis data. Extracted were the six strains, three of which were classified as B. anthracis, and the rest - as closely related bacillus. Demonstrated was the possibility to use this particular complex method for anthrax strains typing and their differentiation from closely related microorganisms
Diagnostic Nutrient Media for Isolation and Identification of Anthrax Agent
Designed is a differential-diagnostic solid nutrient media for isolation and identification of anthrax agent. This media contains: nutrient base (enzymic hydrolysate of fishbone powder), agar-agar, D (+)-sorbite, pH indicator bromthymol blue, and broad-spectrum antibiotic (polymyxin). The media makes it possible to differentiate virulent (capsular) and avirulent (non-capsular) Bacillus anthracis strains, as well as closely related saprophyte microorganisms, depending upon the color and colony morphology
Magnetoelectric ordering of BiFeO3 from the perspective of crystal chemistry
In this paper we examine the role of crystal chemistry factors in creating
conditions for formation of magnetoelectric ordering in BiFeO3. It is generally
accepted that the main reason of the ferroelectric distortion in BiFeO3 is
concerned with a stereochemical activity of the Bi lone pair. However, the lone
pair is stereochemically active in the paraelectric orthorhombic beta-phase as
well. We demonstrate that a crucial role in emerging of phase transitions of
the metal-insulator, paraelectric-ferroelectric and magnetic disorder-order
types belongs to the change of the degree of the lone pair stereochemical
activity - its consecutive increase with the temperature decrease. Using the
structural data, we calculated the sign and strength of magnetic couplings in
BiFeO3 in the range from 945 C down to 25 C and found the couplings, which
undergo the antiferromagnetic-ferromagnetic transition with the temperature
decrease and give rise to the antiferromagnetic ordering and its delay in
regard to temperature, as compared to the ferroelectric ordering. We discuss
the reasons of emerging of the spatially modulated spin structure and its
suppression by doping with La3+.Comment: 18 pages, 5 figures, 3 table
Prediction of inorganic superconductors with quasi-one-dimensional crystal structure
Models of superconductors having a quasi-one-dimensional crystal structure
based on the convoluted into a tube Ginzburg sandwich, which comprises a
layered dielectric-metal-dielectric structure, have been suggested. The
critical crystal chemistry parameters of the Ginzburg sandwich determining the
possibility of the emergence of superconductivity and the Tc value in layered
high-Tc cuprates, which could have the same functions in quasi-one-dimensional
fragments (sandwich-type tubes), have been examined. The crystal structures of
known low-temperature superconductors, in which one can mark out similar
quasi-one- dimensional fragments, have been analyzed. Five compounds with
quasi-one-dimensional structures, which can be considered as potential parents
of new superconductor families, possibly with high transition temperatures,
have been suggested. The methods of doping and modification of these compounds
are provided.Comment: 22 pages, 14 figures and 2 table
ТЕКТОНОФИЗИЧЕСКИЕ ИССЛЕДОВАНИЯ АКТИВНОСТИ РАЗЛОМА ВЕРХОВОГО НА СЕВЕРНОМ СКЛОНЕ КИРГИЗСКОГО ХРЕБТА
An active fault was identified on the northern slope of the Kyrgyz ridge in the area near Research Scientific RAS in Bishkek. It belongs to a large system of crustal faults of the ridge. In our study, tectonophysical methods were used to analyse the regularities of the tectonic stress field reconstructed from seismological data on earthquake focal mechanisms. The stress distribution pattern near the investigated fault suggests its activity either in the recent past or at the present time. This conclusion is supported by the fact that at the eastern and western terminations of the fault, crustal stretching zones are located in a crosswise pattern. The Coulomb stresses on the fault surface were analysed, and the analysis results give grounds to state that its long section crossing the Alamedin river valley should be viewed as potentially hazardous. In the field, we observed abundant broken rock fragments and rock falls in the zone where the fault crosses the Alamedin and Aksu river valleys. It is known that rock falls have occurred more often in the last 3–5 years. The study results show slow movements along the fault. These strike-slip displacements have been going on for at least 10–15 years. According to the modern concepts of the preparation stage of an earthquake source, slow displacements along a fault gradually accelerate several years before an earthquake. Therefore, the studied fault (we named it Verkhovoi) should be considered a potentially hazardous zone wherein earthquakes can occur in future. A magnitude from 6.5 to 7.5 may be expected, depending on whether only the eastern part or the entire fault (i.e. 20 or 50 km, respectively) will be involved in a future seismic event. Further studies of the Verkhovoi fault are needed to clarify a trend in the development of slow sliding along the fault, which will allow understanding whether this process precedes dynamic rock failure (i.e. an earthquake) or tends to gradually decrease.Представлены результаты исследования активного разлома вблизи Научной станции РАН в г. Бишкеке. Выделение этого разлома из большой группы разломов для коры Киргизского хребта выполнено на основе тектонофизических методов анализа закономерности поля тектонических напряжений, полученного из сейсмологических данных о механизмах очагов землетрясений. Распределение напряжений вблизи исследованного безымянного разлома на северном склоне Киргизского хребта говорит о его активности либо в недавнем прошлом, либо в настоящее время. Этот вывод опирается на наличие в его восточном и западном окончании крестообразно расположенных секторов растяжения. Анализ кулоновых напряжений на поверхности разлома показал, что его протяженный участок, пересекающий долину р. Аламедин, следует рассматривать как потенциально опасный. Проведенные полевые геологические работы позволили установить, что в районе пересечения этим разломом долин Аламедин и Аксу происходит обильное образование каменных осыпей и вывалов, причем в последние 3–5 лет активность каменных вывалов возросла. На основе полученных данных мы предполагаем, что исследуемый разлом испытывает медленные движения (сдвиги по простиранию), которые продолжаются уже не менее 10–15 лет. Согласно современным представлениям о стадии подготовки очага землетрясения, за несколько лет до его реализации на разломе начинается медленное, постепенно ускоряющееся смещение, поэтому данный разлом следует рассматривать как потенциально опасный для будущего землетрясения. Ожидаемая магнитуда землетрясения от 6.5 до 7.5 и зависит от реализации восточной части или всего разлома протяженностью соответственно 20 и 50 км. Предполагается дальнейшее изучение этого разлома, названного нами «Верховой», с целью выяснения тенденции развития процесса медленного скольжения в динамический срыв – землетрясение или постепенное затухание скольжения
Interaction between Earthworms and Soil-Inhabiting Anthrax Microbe Spores
Studied are phenotypic and genetic properties of anthrax agent strains, isolated from earthworms retained in infected soil for a period of 20 and 30 days. Discovered is the fact that the presence of worms in the biotope reduces the number of Bacillus anthracis spores by 30-50 %. However, the rest of the spores preserve original properties, and biological and genetic virulence dominants
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