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PubMed | University of South Bohemia, M. Akmullah Bashkir State Pedagogical University, CAS Institute of Botany, Masaryk University and CAS Institute of Microbiology
Type: Journal Article | Journal: Journal of phycology | Year: 2016

Members of the morphologically unusual cyanobacterial family Gomontiellaceae were studied using a polyphasic approach. Cultured strains of Hormoscilla pringsheimii, Starria zimbabwensis, Crinalium magnum, and Crinalium epipsammum were thoroughly examined, and the type specimen of the family, Gomontiella subtubulosa, was investigated. The results of morphological observations using both light microscopy and transmission electron microscopy were consistent with previous reports and provided evidence for the unique morphological and ultrastructural traits of this family. Analysis of the 16S rRNA gene confirmed the monophyletic origin of non-marine repre-sentatives of genera traditionally classified into this family. The family was phylogenetically placed among other groups of filamentous cyanobacterial taxa. The presence of cellulose in the cell wall was analyzed and confirmed in all cultured Gomontiellaceae members using Fourier transform infrared spectroscopy and fluorescence microscopy. Evaluation of toxins produced by the studied strains revealed the hepatotoxin cylindrospermopsin (CYN) in available strains of the genus Hormoscilla. Production of this compound in both Hormoscilla strains was detected using high-performance liquid chromatography in tandem with high resolution mass spectrometry and confirmed by positive PCR amplification of the cyrJ gene from the CYN biosynthetic cluster. To our knowledge, this is the first report of CYN production by soil cyanobacteria, establishing a previously unreported CYN-producing lineage. This study indicates that cyanobacteria of the family Gomontiellaceae form a separate but coherent cluster defined by numerous intriguing morphological, ultrastructural, and biochemical features, and exhibiting a toxic potential worthy of further investigation.


Potapov A.A.,Bashkir State University | Izmailov R.N.,M. Akmullah Bashkir State Pedagogical University | Nandi K.K.,North Bengal University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2016

We study here, using the Mannheim-Kazanas solution of Weyl conformal theory, the mass decomposition in the representative subsample of 57 early-type elliptical lens galaxies of the Sloan Lens Advanced Camera for Surveys (SLACS) on board the Hubble Space Telescope. We begin by showing that the solution need not be an exclusive solution of conformal gravity but can also be viewed as a solution of a class of f(R) gravity theories coupled to nonlinear electrodynamics thereby rendering the ensuing results more universal. Since lensing involves light bending, we shall first show that the solution adds to Schwarzschild light bending caused by the luminous mass (M∗) a positive contribution +γR contrary to the previous results in the literature, thereby resolving a long-standing problem. The cause of the error is critically examined. Next, applying the expressions for light bending together with an input equating Einstein and Weyl angles, we develop a novel algorithm for separating the luminous component from the total lens mass (luminous+dark) within the Einstein radius. Our results indicate that the luminous mass estimates differ from the observed total lens masses by a linear proportionality factor across the subsample, which qualitatively agrees with the common conclusion from a number of different simulations in the literature. In quantitative detail, we observe that the ratios of luminous over total lens mass (f∗) within the Einstein radius of individual galaxies take on values near unity, many of which remarkably fall inside or just marginally outside the specified error bars obtained from a simulation based on the Bruzual-Charlot stellar population synthesis model together with the Salpeter initial mass function favored on the ground of metallicity [Grillo et al., Astron. Astrophys. 501, 461 (2009)]. We shall also calculate the average dark matter density ρ av of individual galaxies within their respective Einstein spheres. To our knowledge, the present approach, being truly analytic, seems to be the first of its kind attempting to provide a new decomposition scheme distinct from the simulational ones. © 2016 American Physical Society.


Potapov A.A.,Bashkir State University | Izmailov R.,M. Akmullah Bashkir State Pedagogical University | Mikolaychuk O.,Bashkir State University | Mikolaychuk N.,Bashkir State University | And 2 more authors.
Journal of Cosmology and Astroparticle Physics | Year: 2015

Recently, Harko et al. (2014) derived an approximate metric of the galactic halo in the Eddington inspired Born-Infeld (EiBI) gravity. In this metric, we show that there is an upper limit ρ 0upper on the central density ρ 0 of dark matter such that stable circular orbits are possible only when the constraint ρ 0 ρ 0upper is satisfied in each galactic sample. To quantify different ρ 0upper for different samples, we follow the novel approach of Edery & Paranjape (1998), where we use as input the geometric halo radius RWR from Weyl gravity and equate it with the dark matter radius RDM from EiBI gravity for the same halo boundary. This input then shows that the known fitted values of ρ 0 obey the constraint ρ 0 ρ 0upper (RWR)-2. Using the mass-to-light ratios giving α , we shall also evaluate ρ 0lower(α -1)MlumRWR-3 and the average dark matter density ρ lower. Quantitatively, it turns out that the interval ρ 0lowerρ 0 ρ 0upper verifies reasonably well against many dark matter dominated low surface brightness (LSB) galaxies for which values of ρ 0 are independently known. The interval holds also in the case of Milky Way galaxy. Qualitatively, the existence of a stability induced upper limit ρ 0upper is a remarkable prediction of the EiBI theory. © 2015 IOP Publishing Ltd and Sissa Medialab srl .


Tamang A.,Darjeeling Government College | Potapov A.A.,Bashkir State University | Lukmanova R.,M. Akmullah Bashkir State Pedagogical University | Izmailov R.,M. Akmullah Bashkir State Pedagogical University | Nandi K.K.,North Bengal University
Classical and Quantum Gravity | Year: 2015

In this paper, we wish to investigate certain observable effects in the recently obtained wormhole solution of the Eddington-inspired Born-Infeld (EiBI) theory, which generalizes the zero-mass Ellis-Bronnikov wormhole of general relativity. The solutions of EiBI theory contain an extra parameter κ having the inverse dimension of the cosmological constant Λ, and which is expected to modify various general relativistic observables such as the masses of wormhole mouths, tidal forces and light deflection. A remarkable result is that a non-zero κ could prevent the tidal forces in the geodesic orthonormal frame from becoming arbitrarily large near a small throat radius (r0 ∼0) contrary to what happens near a small Schwarzschild horizon radius (M∼0). The role of κ in the flare-out and energy conditions is also analyzed, which reveals that the energy conditions are violated. We show that the exotic matter in the EiBI wormhole cannot be interpreted as a phantom (ω = pr/ρ <-1) or ghost field φ of general relativity due to the fact that both ρ and p r are negative for all κ. © 2015 IOP Publishing Ltd.


Izmailov R.,M. Akmullah Bashkir State Pedagogical University | Potapov A.A.,Bashkir State University | Filippov A.I.,Bashkir State University | Ghosh M.,North Bengal University | Nandi K.K.,North Bengal University
Modern Physics Letters A | Year: 2015

We investigate the stability of circular material orbits in the analytic galactic metric recently derived by Harko et al., Mod. Phys. Lett. A29, 1450049 (2014). It turns out that stability depends more strongly on the dark matter central density ρ0 than on other parameters of the solution. This property then yields an upper limit on ρ0 for each individual galaxy, which we call here ρ0upper, such that stable circular orbits are possible only when the constraint ρ0 ≤ ρ0upper is satisfied. This is our new result. To approximately quantify the upper limit, we consider as a familiar example our Milky Way galaxy that has a projected dark matter radius RDM∼180 kpc and find that ρ0upper ∼ 2.37 × 1011∼M; o ∼ kpc-3. This limit turns out to be about four orders of magnitude larger than the latest data on central density ρ0 arising from the fit to the Navarro-Frenk-White (NFW) and Burkert density profiles. Such consistency indicates that the Eddington-inspired Born-Infeld (EiBI) solution could qualify as yet another viable alternative model for dark matter. © 2015 World Scientific Publishing Company.


Belavin A.M.,Perm State University | Krylasova N.B.,Perm State University | Ivanov V.A.,M. Akmullah Bashkir State Pedagogical University
European Journal of Science and Theology | Year: 2015

Archaeological materials indicate that Urals of the early medieval period can be considered as a part of the territory of historical ancestral home of the Magyars. After Hungarians moving to the west, Urals has long been a part of the Finno-Magyar ecumene, which can be considered as the legendary Magna Hungaria. © 2015, European Journal of Science and Theology. All right reserved.


Borisova V.,M. Akmullah Bashkir State Pedagogical University | Schaulov S.,Moscow State University
European Journal of Science and Theology | Year: 2015

In this article the dichotomy of perception of the novel „Idiot‟ in the context of the last novel „Brothers Karamazov‟ by F. M. Dostoyevsky is discussed. The researchers define its nature and origins of the ambiguous reception. The alternative perception of the novel „Idiot‟ and its main hero are determined by the author. According to the perceptive point of view the writer‟s text is the „space of freedom‟ for a reader. This fact is also defined by the strategy of the author. Dostoyevsky uses the device of a reader‟s „failed expectations‟ associated with the miracle of Christ‟s resurrection. © 2015, Ecozone, OAIMDD. All right reserved.


Khaybullina L.S.,M. Akmullah Bashkir State Pedagogical University | Gaysina L.A.,M. Akmullah Bashkir State Pedagogical University | Johansen J.R.,John Carroll University | Krautova M.,University of South Bohemia
Fottea | Year: 2010

Forest soils of the Great Smoky Mountains National Park were examined for soil algae as part of the All Taxa Biodiversity Inventory underway in that park. Soils of both mature and secondary growth forests were sampled, along with samples from rocks and tree bark. A total of 42 taxa were observed, representing Cyanobacteria (3 species), Chlorophyceae (12 species), Trebouxiophyceae (18 species), Ulvophyceae (3 species), Klebsormidiophyceae (1 species), Zygnematophyceae (2 species), Tribophyta (3 species), Eustigmatophyta (1 species), Euglenophyta (1 species), and Dinophyta (1 species). Twenty new taxa records for the park were established. © Czech Phycological Society.


Khaybullina A.,M. Akmullah Bashkir State Pedagogical University | Akhtaryanova G.,M. Akmullah Bashkir State Pedagogical University | Mingazova R.,M. Akmullah Bashkir State Pedagogical University | Saha D.,M. Akmullah Bashkir State Pedagogical University | Izmailov R.,M. Akmullah Bashkir State Pedagogical University
International Journal of Theoretical Physics | Year: 2014

We investigate the stability regions of the thin-shells obtained by gluing the exterior Schwarzschild vacuum with two distinct classes of Ellis wormholes, one with zero and the other with nonzero total mass. Using the new concepts of thin-shell "mass" and of "external force" discovered recently by Garcia, Lobo and Visser, we shall apply their method to the explicit cases where some of the energy conditions in the bulk (on two sides) are violated. The stability regions are analyzed and the energetics is briefly discussed. Remarkably, we find that the stability zones are quite similar although the classes of Ellis wormholes are different. By the present examples, we confirm that the stability zones indicated by the force constraint (involving Φ and its derivatives) are more complete but restrictive than those from the mass constraint (not involving Φ). © 2013 Springer Science+Business Media New York.


Lukmanova R.,M. Akmullah Bashkir State Pedagogical University | Kulbakova A.,M. Akmullah Bashkir State Pedagogical University | Izmailov R.,M. Akmullah Bashkir State Pedagogical University | Potapov A.A.,Bashkir State University
International Journal of Theoretical Physics | Year: 2016

Gravitational lensing is the effect of light bending in a gravitational field. It can be used as a possible observational method to detect or exclude the existence of wormholes. In this work, we extend the work by Abe on gravitational microlensing by Ellis wormhole by including the second order deflection term. Using the lens equation and definition of Einstein radius, we find the angular locations of the physical image inside and outside Einstein ring. The work contains a comparative analysis of light curves between the Schwarzschild black hole and the Ellis wormhole that can be used to distinguish such objects though such distinctions are too minute to be observable even in the near future. We also tabulate the optical depth and event rate for lensing by bulge and Large Magellanic Cloud (LMC) stars. © 2016 Springer Science+Business Media New York

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