428 research outputs found

    Variability of the structure of winter microbial communities in Chelyabinsk lakes

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    Microorganisms form complex and dynamic communities that play a key role in the biogeochemical cycles of lakes. A high level of urbanization is currently a serious threat to bacterial communities and the ecosystem of freshwater bodies. To assess the contribution of anthropogenic load to variations in the structure of winter microbial communities in lakes, microorganisms of four water bodies of Chelyabinsk region were studied for the first time. We used cultural, chromatography-mass spectrometric, and modern methods of statistical data processing (particularly, multivariate exploratory analysis and canonical analysis of correspondences). The research showed that the composition of winter microbial communities in lakes Chebarkul’, Smolino, Pervoye, and Shershenevskoye Reservoir did not differ significantly between the main phyla of microorganisms. The dominant microorganisms were found to be of the Firmicutes phylum and Actinobacteria phylum. The structure of bacterial communities had special features depending on the characteristics of the water body and the sampling depths. Thus, in the lakes Smolino, Pervoye, and Shershenevskoye Reservoir, an important role was played by associations between microorganisms – indicators of fecal contamination: coliform bacteria and Enterococcus. On the contrary, in Chebarkul’ Lake, members of the genus Bacillus, which are natural bioremediators, formed stable winter associations. However, the differences between water bodies and sampling depths reflected 28.1% and 9.8% of the variability of the winter microbial communities, respectively. The largest contribution (about 60%) to the variability of the structure was made by intra-water processes, which determined the high heterogeneity of samples from different water areas. We assume that an important role in this variability was played by the high anthropogenic impact in a large industrial metropolis. In our opinion, this line of research is very promising for addressing key environmental issues

    Spectral analysis of X-ray pulsars with the INTEGRAL observatory

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    We studied spectra for 34 accretion-powered X-ray and one millisecond pulsars that were within the field of view of the INTEGRAL observatory over two years (December 2002 - January 2005) of its in-orbit operation and that were detected by its instruments at a statistically significant level (>8 sigma in the energy range 18-60 keV). There are seven recently discovered objects of this class among the pulsars studied: 2RXP J130159.6-635806, IGR/AX J16320-4751, IGR J16358-4726, AX J163904-4642, IGR J16465-4507, SAX/IGR J18027-2017 and AX J1841.0-0535. We analyze the evolution of spectral parameters as a function of the intensity of the sources and compare these with the results of previous studies

    NOE Effect of Sodium Dodecyl Sulfate in Monomeric and Micellar Systems by NMR Spectroscopy

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    This paper describes the particular nuclear Overhauser effect (NOE) of sodium dodecyl sulfate (SDS) in monomeric and micellar systems. Two-dimensional NOE spectroscopy nuclear magnetic resonance (NMR) spectra of SDS in solution with concentration lower and higher than critical micellar concentration were recorded. In the first case diagonal and cross-peaks have different signs, and the opposite one was in the second case. This paper discusses theoretical background of this effect and we supposed that particular NOE can be used for inspection of SDS micelle formation during NMR researches. As a rough estimate of micelles formation an approach based on the difference between the chemical shifts in the monomer and micellar form of SDS was used. © 2014 Springer-Verlag Wien

    Using high-chromium iron as material for production of the equipping components of mine shafts

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    This paper deals with service conditions of shaft equipment, in particular, inserts of sliding bearings for the purpose of increasing service life due to material substitution and wear resistance increase. As a new material high-chromium irons are offered. Studies are conducted on a microstructure and wear resistance of prototypes is measured. Experimental data are treated by methods of mathematical statistics which confirm reliability of results. The results obtained make it possible to suggest using high-chromium irons as the direct material to produce inserts of sliding bearings

    Study of the Fast X-Ray Transient XTE J1901+014 Based on INTEGRAL, RXTE and ROSAT Data

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    The source XTE J1901+014 discovered by the RXTE observatory during an intense outburst of hard radiation and classified as a fast X-ray transient is studied. The source's spectral characteristics in the quiescent state have been investigated for the first time both in the soft X-ray energy range (0.6-20 keV) based on ROSAT and RXTE data and in the hard energy range (>20 keV) based on INTEGRAL data. A timing analysis of the source's properties has revealed weak nonperiodic bursts of activity on time scales of several tens of seconds and two intense (∌\sim0.5-1 Crab) outbursts more than several hundred seconds in duration. Certain assumptions about the nature of the object under study are made.Comment: 19 pages, 7 figure

    Economic concept of food development of Russian market

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    At present, the Russian economy is developing in the conditions of imposed sanctions on high-tech means of production by foreign countries. In this situation, the development vector is the formation of import substitution policies and the solution of food safety issues for various types of food products that are strategically important for human life. Meeting the needs of the country's population with its own production is a priority for the development of the agrarian market, which makes it possible to develop the production agrarian sector, the processing and trade sphere, to create additional jobs, thereby improving the quality and standard of living of people.peer-reviewe

    Anabar Region of Yakutia in the XX — Early XXI Centuries: Characteristics of the Local Cultural Landscape

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    The features of the ethnocultural landscape of the Anabar national (Dolgan-Evenk) ulus of the Republic of Sakha (Yakutia) are considered. Attention is paid to the main components of cultural landscapes: local communities and traditional economy. In the study area, the retrospective analysis made it possible to identify the dynamics of the  number and settlement of residents, to state the modern functioning of two rural local communities: Saskylakh  and Yuryung-khainsky. It is argued that the sustainability and preservation of traditional sectors of the economy are due to the adaptation of the local population to natural landscapes. It is noted that during the XX — early XXI centuries, the traditional economic activities of the indigenous population, represented by different ethnic groups  that originally inhabited the territory of the ulus, remained unchanged and, despite all the socio-economic transformations, remain vital and common for the Anabarians. The article presents the results of the analysis of a sociological survey and an associative experiment, which revealed the features of the linguistic landscape of the area under consideration, depending on different layers of self-awareness: external, with a predominance of Russian-language text in the linguistic appearance of the settlements under study; individual, with a predominance of the Yakut language in intergroup communication; and the subconscious, which revealed the dominance of the Dolgan cultural codes. It has been established that the cultural landscape of the Anabar ulus is the result of  centuries-old interaction of indigenous ethnic groups inhabiting this area: Dolgans, Evenks, Yakuts and Russians
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