Peculiarities of a Colloidal Polysaccharide of Newly Isolated Iron Oxidizing Bacteria in Armenia

Microorganisms belonging to different systematic and physiological groups produce various intra- and extracellular polysaccharides, which both play an important role in the life of microorganisms and have great practical application. Iron and sulfur oxidizing bacteria produce capsular (EPS) and colloidal polysaccharides. At present the properties and functional role of EPS are well studied. However, the properties of the colloidal polysaccharides produced by iron oxidizing bacteria have not been sufficiently explored. A new iron oxidizing bacteria Leptospirillum ferriphilium CC was isolated from sulfide ores of Armenia. Its morphological and physiological features have been studied. A colloidal polysaccharide has been isolated with the use of an original method developed by the authors, and its physical and chemical properties have been studied. It has been shown that the colloidal polysaccharide consists of three different monomers- glucose, fructose, mannose.. Investigations with a complex method of optical polarization microscopy and analytical programs allowed determining the size, shape change, perimeter, degree of hydratation and crystallization at 0.07% and 0.04% of polysaccharide concentration. It was shown that the size of a polysaccharide colloidal particle does not much depend on polysaccharide concentration, however, the number of identical colloidal formations is dependent on the concentration of polysaccharide

Giant vortices, vortex rings and reentrant behavior in type-1.5 superconductors

We predict that in a bulk type-1.5 superconductor the competing magnetic responses of the two components of the order parameter can result in a vortex interaction that generates group-stabilized giant vortices and unusual vortex rings in the absence of any extrinsic pinning or confinement mechanism. We also find within the Ginzburg-Landau theory a rich phase diagram with successions of behaviors like type-1 -> type-1.5 -> type-2 -> type-1.5 as temperature decreases.Comment: 5 pages, 4 figure

Experimental Investigation of the Nature of the Knee in the Primary Cosmic Ray Energy Spectrum with the GAMMA experiment

We present preliminary results obtained by a novel difference method for the study of the nature of the knee in the energy spectrum of the primary cosmic radiation. We have applied this method to data from the GAMMA experiment in Armenia. The analysis provides evidence for the possible existence of a nearby source of primary cosmic rays in the Southern hemisphere.Comment: 17 pages, 5 figure

Fermionic vacuum currents in topologically nontrivial braneworlds: Two-brane geometry

The vacuum expectation value (VEV) of the fermionic current density is investigated in the geometry of two parallel branes in locally AdS spacetime with a part of spatial dimensions compactified to a torus. Along the toral dimensions quasiperiodicity conditions are imposed with general phases and the presence of a constant gauge field is assumed. Different types of boundary conditions are discussed on the branes, including the bag boundary condition and the conditions arising in $Z_{2}$-symmetric braneworld models. Nonzero vacuum currents appear along the compact dimensions only. In the region between the branes they are decomposed into the brane-free and brane-induced contributions. Both these contributions are periodic functions of the magnetic flux enclosed by compact dimensions with the period equal to the flux quantum. Depending on the boundary conditions, the presence of the branes can either increase or decrease the vacuum current density. For a part of boundary conditions, a memory effect is present in the limit when one of the branes tends to the AdS boundary. Unlike to the fermion condensate and the VEV of the energy-momentum tensor, the VEV of the current density is finite on the branes. Applications are given to higher-dimensional generalizations of the Randall-Sundrum models with two branes and with toroidally compact subspace. The features of the fermionic current are discussed in odd-dimensional parity and time-reversal symmetric models. The corresponding results for three-dimensional spacetime are applied to finite length curved graphene tubes threaded by a magnetic flux. It is shown that a nonzero current density can also appear in the absence of the magnetic flux if the fields corresponding to two different points of the Brillouin zone obey different boundary conditions on the tube edges.Comment: 33 pages, 7 figures, PACS numbers: 04.62.+v, 03.70.+k, 98.80.-k, 61.46.F

Fermionic currents in topologically nontrivial braneworlds

We investigate the influence of a brane on the vacuum expectation value (VEV) of the current density for a charged fermionic field in background of locally AdS spacetime with an arbitrary number of toroidally compact dimensions and in the presence of a constant gauge field. Along compact dimensions the field operator obeys quasiperiodicity conditions with arbitrary phases and on the brane it is constrained by the bag boundary condition. The VEVs for the charge density and the components of the current density along uncompact dimensions vanish. The components along compact dimensions are decomposed into the brane-free and brane-induced contributions. The behavior of the latter in various asymptotic regions of the parameters is investigated. It particular, it is shown that the brane-induced contribution is mainly located near the brane and vanishes on the AdS boundary and on the horizon. An important feature is the finiteness of the current density on the brane. Applications are given to $Z_2$-symmetric braneworlds of the Randall-Sundrum type with compact dimensions for two classes of boundary conditions on the fermionic field. In the special case of three-dimensional spacetime, the corresponding results are applied for the investigation of the edge effects on the ground state current density induced in curved graphene tubes by an enclosed magnetic flux.Comment: 32 pages, 9 figures, PACS numbers: 04.62.+v, 03.70.+k, 98.80.-k, 61.46.F

Dependence of some physiological indicators of generative and vegetative organs of Sambucus nigra on habitat conditions

We carried out studies on water deficiency of Sambucus nigra L. (black elderberry) plant leaves extract and fruit juice, relative turgidity, sucrose content in fruits, chlorophyll content in the leaves, as well as gas exchange rates in the leaves, in particular, the changes in the concentrations of oxygen released during photosynthesis by leaves and carbon dioxide released during leaf respiration depending on habitat conditions (altitude of the habitat, position of slopes, average annual precipitation). Taking into account the difference in climatic conditions and the generality of some indicators, Vanadzor (1326–1600 m above sea level) and Stepanavan (1400–1830 m above sea level) regions of Lori Province, "Dilijan" National Park, Lake Parz, and the forest areas adjacent to the city of Dilijan (1240–1612 m above sea level) in Tavush Province in Armenia were chosen as the research sites. The test samples were taken from eight different test sites in Lori and Tavush provinces. Tavush Province is more humid than Lori Province. The highest rate of water deficiency in the leaves of the studied plants was recorded in S. nigra f. laciniata (L.) Zabel., and the lowest in S. nigra in Vanadzor forest. It can be assumed that the index of water deficiency in the leaves may depend on the position of the slopes of the test sites and the value of the filtration coefficient of the soil types. On the north-facing slope at the height of 1341 m above sea level and on the south-facing slope at the height of 1830 m above sea level, the values of water deficiency of the leaves are almost the same. Such data allows us to assume that the degree of water deficiency in the leaves is also affected by the filtration coefficient of habitat soil types. In two points that have north-facing positions, the water deficiency of leaves at the height of 1341 m above sea level is 2.14 times more than at the height of 1328 m above sea level. At 1328 m above sea level the filtration coefficient is small and the plant absorbs a lot of water. Based on the data we received we obtained rankings of plants according to the different criteria of the experimental plants: water deficiency in leaves tissues, relative turgidity, the sum of chlorophylls in the leaves, the sucrose content in the fruits, percentage of oxygen released as a result of photosynthesis, percentage of carbon dioxide released as a result of respiration. We found a certain dependence between the indicators of the water regime and the height above sea level of the researched habitats. We also found out that the water regime is influenced by certain microclimatic conditions such as the position of the slopes, whether they are north or south facing, as well as the average annual precipitation. Knowing the physiological processes taking place in the vegetative and generative organs of the S. nigra plant is important from the point of view of evaluating the intensity of growth and development of the generative organs. We consider that the results of the study will be applicable in the process of plant selection based on the indicators of the physiological processes taking place in the plant organism

The Geometry Monitoring System of the ALICE Dimuon Spectrometer: Overview

ALIC

Observation of Resonant Diffusive Radiation in Random Multilayered Systems

Diffusive Radiation is a new type of radiation predicted to occur in randomly inhomogeneous media due to the multiple scattering of pseudophotons. This theoretical effect is now observed experimentally. The radiation is generated by the passage of electrons of energy 200KeV-2.2MeV through a random stack of films in the visible light region. The radiation intensity increases resonantly provided the Cherenkov condition is satisfied for the average dielectric constant of the medium. The observed angular dependence and electron resonance energy are in agreement with the theoretical predictions. These observations open a road to application of diffusive radiation in particle detection, astrophysics, soft X-ray generation and etc.. `Comment: 4pages, 4figure